skip to content

Darwin Correspondence Project

From J. J. Weir   [1–13] May 18691

6 Haddo Villas | Blackheath SE

May 1869

My Dear Sir

I send by this days post a copy of a short paper on Insects and Insectivorous birds.— The results yet arrived at are meagre, but they point in one direction & support Wallaces theory on the subject.—2

I have recently twice visited the South Downs during the lambing season and was very much surprised to see how very far from being white the lambs were even when some weeks old.—3

The flocks were of the choicest character, one my Brother in Laws was in the farm just vacated by the late John Ellmans son & the rams used as sires were of great value, yet the lambs reminded one of Jacobs spotted & speckled, some had large patches of color all over the back, & the faces of many were mottled, & the ewes even were often black & white, yet so powerfully has selection acted entirely to produce a perfect adult, that all these would ultimately have white wool and light brown faces (the true South Down has never a black face).—4

I was much interested to find from a recent visitor there that in the remote Island of St. Kilda the sheep are still even in the adult state brown.—5

I may further remark when on the subject of sheep that this season, much below the average number of twin lambs have been produced, the Flock masters think that insufficient food last autumn was the cause.—

I endeavoured to ascertain whether any lambs were ever produced without tails but could hear of none.—

This I think remarkable because the sheep dogs which have had their tails amputated in a similar manner, are now commonly pupped tailless.—6

Believe me | My Dear Sir | Yours sincerely | J Jenner Weir

C Darwin Esqr.

CD annotations

1.1 I send … subject.— 1.3] crossed pencil
2.1 I have … brown.— 4.2] ‘South down lambs mottled with Black’ added red crayon
5.1 I may … tailless— 7.2] crossed pencil
Top of letter: ‘Embryology Sheep of South Downs | Reversion?’ pencil


The date range is established by the relationship between this letter and the letter to J. J. Weir, 13 May [1869].
Weir refers to ‘On insects and insectivorous birds; and especially on the relation between the colour and the edibility of Lepidoptera and their larvae’ (Weir 1869), which was published in the April 1869 issue of Transactions of the Entomological Society of London. Alfred Russel Wallace had theorised that bright colour in caterpillars was protective (see letter from A. R. Wallace, 10 March 1869 and nn. 2 and 3).
Weir refers to hills around Lewes in East Sussex, where the Southdown breed of sheep originated. CD had discussed the colour of Southdown lambs in Variation 2: 30.
John Ellman (1753–1832) was well known for his work in developing the Southdown sheep at Place Farm, Glynde, near Lewes. His son, John Ellman (1787–1867), took over the farm in 1829 (Farrant 1978). The son of the second John Ellman whom Weir refers to may have been Robert Harvey Ellman. The early breed standard described the face as long and speckled (ibid., p. 78), but the modern breed standard refers to the face as mouse-coloured (, accessed 2 November 2007). Weir also refers to the Jacob sheep, an ancient, multi-horned breed with a piebald fleece. Weir’s brother-in-law has not been identified.
Weir refers to Soay sheep, native to the island of Soay in the St Kilda archipelago of western Scotland. It is considered one of the oldest breeds (Ponting 1980, p. 69).
CD had recently corresponded with William Chester Tait concerning Tait’s observations of the inheritance of taillessness in dogs (see letters from W. C. Tait, 26 January 1869 and 19 February 1869).


Farrant, Sue. 1978. John Ellman of Glynde in Sussex. Agricultural History Review 26: 77–88.

Ponting, Kenneth. 1980. Sheep of the world. Poole: Blandford Press.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Weir, John Jenner. 1869. On insects and insectivorous birds; and especially on the relation between the colour and the edibility of Lepidoptera and their larvae. [Read 1 March 1869.] Transactions of the Entomological Society of London (1869): 21–6.


South Down sheep: variability in colouring and patterning of lambs compared with constancy of adult coat.

Letter details

Letter no.
John Jenner Weir
Charles Robert Darwin
Sent from
Source of text
DAR 181: 79
Physical description
ALS 8pp †

Please cite as

Darwin Correspondence Project, “Letter no. 6723,” accessed on 14 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 17